Turkish authorities on Wednesday rounded up two dozen suspected members of a radical leftist group behind a bloody hostage standoff that left a top Istanbul prosecutor dead and shocked the country.
Funeral ceremonies were being held for prosecutor Mehmet Selim Kiraz, who had been investigating the politically-sensitive case of a teenager who died of injuries inflicted by police during anti-government protests in 2013.
Police late on Tuesday launched an operation to free Kiraz after an hours-long standoff with his captors but the official, who had sustained gunshot wounds, died shortly after arriving at hospital.
It was not clear from where the shots that killed him were fired.
Both his captors, two men in their 20s affiliated to the outlawed Marxist Revolutionary People's Liberation Party-Front (DHKP-C), were killed in the police operation.
Turkish authorities on Wednesday detained 22 suspected members of the group in the southern city of Antalya after receiving a tip-off they were planning further attacks, the Dogan news agency reported.
A lawyer for the suspects told Dogan that the claims were baseless and the group was going to release a statement later in the day.
The DHKP-C is considered a terrorist group by Turkey, the European Union and the United States and has carried out a string of attacks in Turkey in the past.
A ceremony to remember Kiraz was to take place at the Istanbul Caglayan Palace of Justice where he worked and the hostage drama unfolded.
Hundreds of lawyers, prosecutors and staff stood in respect on every floor of the giant building -- said to be the largest courthouse in Europe -- and unfurled a giant Turkish flag from the top floor.
"We will not forget you, our martyr," read a gigantic banner.
He was later to be buried in a funeral at the Eyup Sultan Mosque in Istanbul to be attended by Prime Minister Ahmet Davutoglu, the official Anatolia news agency said.
"The day we went into darkness," said the daily Cumhuriyet after a day which also saw Turkey's worst nationwide power cut in 15 years.
"Black Tuesday," said the Hurriyet daily.
Kiraz had been leading a hotly-politicised investigation into the killing of teenager Berkin Elvan, who died in March last year after spending 269 days in a coma from injuries inflicted by police in anti-government protests in the summer of 2013.
So far no-one has been brought to trial for the crime and the captors demanded that Kiraz hand over the names of the suspects and force them to confess.
Publishing photos of the prosecutor with his mouth bound and a gun to his head, they threatened to kill him if their demands were not met.
Davutoglu said it was an "attack against the Turkish judiciary, Turkish democracy and all the citizens in Turkey."
"No one should doubt that we will continue to fight against terrorism with determination and take whatever steps necessary," he added.
President Recep Tayyip Erdogan, arriving on a visit to Romania, said the attackers had entered the courthouse disguised in legal robes.
He said Kiraz had suffered three gunshots to the head and two to his body.
Turkish media reports said the attackers had carried fake lawyers' ID that allowed them to get round security checks.
Kiraz pressed a panic button after he was seized but the attackers had already locked the doors, the Milliyet daily said.
The circumstances of the police operation were not immediately clear but Istanbul police said it was launched after they heard gunshots coming from the office where he was held.
Energy Minister Taner Yildiz vehemently denied there was any link between the hostage drama and the power cut, after opposition leader Kemal Kilicdaroglu claimed the power could have been cut intentionally to assist the captors.
The drama came at time of intensifying political tensions in Turkey ahead of June 7 legislative elections.
Erdogan's ruling Justice and Development Party (AKP) is seeking a landslide victory, which would allow it change the constitution to boost the powers of the presidency which he assumed in 2014 after over a decade as prime minister.